Abstract

Inspections of moiré fringe characteristics, such as period and orientation, conventionally are done by two approaches; namely,
parametric equation and Fourier analysis methods. In some cases these methods yield different results. This inconsistency is removed by revising the derivation of the indicial equation for moiré fringes by the parametric equation method.

Figures (2)

Orientation of the two straight-line gratings in the xy plane. Lines of first grating are parallel to and those of the second make a small angle θ with the y axis. They have periods d1 and d2,
and are indicated by h and k parameters, respectively.

Two families of infinite (M′,N′) lines families in the lattice point: (a) (1,−1) line family and (b) (2,−1) line family. The value of index p in each line family has been calculated by Eq. (13) for corresponding values of M′ and N′.